Transmission bandwidth demands in telecommunication networks (e.g., the Internet) appear to be ever increasing and solutions are being sought to support this bandwidth demand. One solution to problem is to use fiber-optic networks, where wavelength-division-multiplexing (WDM) technology is used to support the ever growing demand in optical networks for higher data rates.
Conventional optical switched networks typically use wavelength routing techniques that require optical-electrical-optical (OEO) conversion of optical signals. OEO conversion can typically require about ten milliseconds at each switching node in the optical network, which is very costly, and potentially creates a traffic bottleneck for the optical switched network. In addition, current optical switch technologies cannot efficiently support “bursty” nature of the traffic that is often experienced in packet communication applications (e.g., the Internet).
A large network can be implemented using several sub-networks. For example, a large network to support Internet traffic can be divided into a large number of relatively small access networks operated by Internet service providers (ISPs), which are coupled to a number of metropolitan area networks (Optical MANs), which are in turn coupled to a large “backbone” wide area network (WAN). While the local-area networks (LANs) can be relatively low bandwidth, the optical MANs and WANs typically require high bandwidth in order to provide a level of service demanded by their high-end users.